Photoimageable material of polymeric material having organic sulfide and photo-oxidation sensitizer

ABSTRACT

The present invention relates to a photoimaging process whereby a polymeric film containing sulfide functionality is selectively exposed to incident radiation in the presence of oxygen and a photosensitizer so that the sulfur functionality is photooxidized to produce a latent image which may then be developed. Polymeric films containing photooxidizable organic sulfide functionality and preferably additional carbon-carbon double bond unsaturation, which are capable of being used in the foregoing process are also included within the scope of the present invention.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.756,034, filed Dec. 30, 1976 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to the production of photoimages by a processadaptable to a wide variety of graphic arts applications and whichcomprises the production of developable latent images in a polymericsubstrate by the direct photooxidation of organic sulfide containingfunctional groups in the polymer. The invention is also directed to thesulfur containing polymer film materials per se.

2. Description of the Prior Art

The photoimaging of polymeric films by selective exposure to irradiationto effect localized cross-linking or curing is well known. Themechanisms involved frequently depend upon polymerization ofcross-linking which is initiated by free radicals and which requires thepresence of a peroxide or other source of free radicals. The exposedregions of the polymer film are generally rendered relatively insolublewhen compared with the unexposed regions thus providing a latent imagewhich may be developed by washing with a suitable solvent.

Photooxidative processes for imaging polymer films have been describedin a number of issued U.S. Pat. Nos. e.g., 3,790,389, Heimsch et al;3,801,320, Erickson; 3,847,609 and 3,926,642 both issued to Breslow etal, and 3,846,266, Duynstee et al. These processes achieve photoimagingby the photooxidation of ##STR1## unsaturation in polymer films byexposure in the presence of oxygen and a photosensitizer. Thephotooxidation results in the production of hydroperoxides attached tothe polymer chain at the site of the allylic unsaturation. The latenthydroperoxide polymer image may then be amplified and/or developed by avariety of techniques. The present invention does not depend for imagingupon the hydroperoxidation of ##STR2## unsaturation, but the speed ofthe film is enhanced by the further presence of ##STR3## unsaturation inthe polymer substrate. In film embodiments where higher speed is adesirable property the co-presence of photooxidizable sulfurfunctiontality with ##STR4## unsaturation constitutes a preferredembodiment of the invention.

SUMMARY OF THE INVENTION

It has now been discovered that photoimaging may be accomplished by theselective exposure of certain organic sulfide containing polymers tolight in the presence of oxygen and a suitable photosensitizer.

Polymeric films suitable for use in the present invention mustessentially contain adequate sulfide, e.g., --C--S--C-- type, sulfurfunctionality. Suitable polymers can be obtained in a variety of ways ofwhich the following are illustrative:

(a) Polymerization of a monomer in the presence of a thiol or disulfide,

(b) The addition of a thiol to a preformed polymer containing anappropriate reactive site, such as a carboncarbon double bond,

(c) Polymerization or copolymerization of sulfide containing monomers.

Species of sulfur polymers also expected to be operable are polymerswith --S-- or --S--S-- units in the main chain.

The polymers used in this invention may be saturated or unsaturated, andthe latter generally exhibit greater speed.

The photosensitizer is preferably blended into the polymer by admixtureprior to film formation, but may also be incorporated after filmformation. The photosensitizer must be capable of absorbing photons andthen converting oxygen from a triplet to a highly reactive singlet statein which the oxygen reacts with the sulfur functionality in the polymer.The photosensitizer is generally regenerated at the end of the cycle.

Exposure of polymer films in accordance with this invention can beaccomplished by techniques well known in the art.

Development of polymer films which have been photoimaged in accordancewith this invention can be carried out by application of solvents toremove the relatively soluble portions of the film, or by techniquesdependent upon other changes in film properties.

The polymer composition, usually incorporating admixed photosensitizermay be formed into a film or other structural configuration useful ingraphic arts applications, such as, by solution coating the polymer ontoa support.

DETAILED DESCRIPTION OF THE INVENTION

Polymer substrates suitable for use in this invention include anypolymer comprising a sufficient amount of photooxidizable organicsulfide functionality such that a latent developable image can beproduced by selective exposure to radiation of portions of a body of thepolymer.

Satisfactory polymers may be produced in any of the following manners:

(1) Polymerizing monomers in the presence of a thiol or disulfide.Useful starting materials for such polymerization include any of thefollowing monomers used to produce either homopolymers or appropriatecopolymers: styrene, methyl methacrylate, butyl acrylate, butadiene,isoprene, acrylonitrile, ethylene, propylene, etc.

When the polymerization is conducted in the presence of a thiolcompound, a cross-linking agent, such as, divinyl benzene or trimethylolpropane trimethyacrylate or others well known in the art ofcross-linking polymers must also be used.

While other polymerization methods might possibly be employed, emulsionpolymerization is particularly suitable as it results in discretecross-linked particles which can be coated to produce film materials byapplication from a benzene or like dispersion.

Illustrative of thiols which may be employed in this process are alkylmercaptans, such as, n-dodecyl mercaptan, tert dodecyl mercaptan,p-thiocresol, pentaerythritol tetrakis (β-mercaptopropionate), andthioglycerol.

(2) Introduction of sulfide functionality into preformed polymers by theaddition of a thiol at an unsaturated site, e.g., a ##STR5## site orother reactive site on the polymer. Suitable polymers include, forexample, butadiene or isoprene polymers or copolymers including bothinternal and pendant types of unsaturation. Polymers made by this methodcan be active and soluble, i.e., they need not be cross-linked, incontrast to the photopolymers prepared by the preceding method.Cross-linked polymeric starting materials may be used but are notrequired.

The fact that such polymers are functional in the invention is thoughtto involve sulfide functionality being introduced at more than one pointin the polymeric moiety (chain or particle) in polymers produced by thismethod. Representative of this type of polymer are styrene-butadiene andmethyl methacrylate-butadiene copolymers.

(3) Polymerizing or copolymerizing sulfur containing monomers such asvinyl sulfides, ethylthioethyl methacrylates, styrenes with sulfide ringsubstitution, etc.

The resulting polymeric substrates containing photooxidizable sulfidefunctionality may include, for example, polyolefins such aspolyethylene, polypropylene, polymers of diolefins, such aspolybutadiene, polymers of alpha, beta-unsaturated carboxlyic acidesters, acrylate or methacrylate esters, addition polymers ofunsaturated hydrocarbons, vinylidene polymers, condensation polymers,such as, phenolformaldehydes, polyamides, such as nylons, etc. andvarious copolymers of the foregoing types of materials.

In addition to the above-described polymers it is believed that relatedspecies of sulfide containing polymers should be useful in similarphotooxidation/photoimaging processes. For example polymers with --S--or --S--S-- as units in the main polymer chain, e.g. poly(ethylenesulfide), poly(propylene sulfide) or Thiokol polysulfides such as may beprepared by the condensation of certain organic dihalides with Na₂ S,SCl₂, S₂ Cl, etc.

With respect to the concentration of photosensitizer, or more properlyphotooxidation sensitizer, the appropriate amount will depend on thespecific polymer/sensitizer/exposure system to be employed and will haveto be worked out empirically for each case. Generally, sufficientphotooxidation sensitizer is added to generate sufficient singlet oxygento set a developable image by reaction with the sulfur functionality ofthe polymer substrate. Using tetraphenylporphin (TPP), for example, arange of from about 0.1 mg to 10 mg/gm of polymer would generally beemployed with a range of from about 1 to 5 mg/gm of polymer beingpreferred.

Any suitable photosensitizer may be used. TPP and other sensitizers ofthe porphin type and 1,8-dinaphthylenethiophene are preferred.

It would be impossible for applicant to experiment with all of thephotooxidation sensitizers known in the art, but it is expected thatmany from the following types would be useful and it would be a matterof routine and simple experimentation for a person skilled in the art toselect additional satisfactory sensitizers from the followingcategories:

(1) The aromatic group meso-substituted porphin compounds. Among sucharomatic substituted porphins are the ms-tetraarylporphins (ms-meso).These compounds are those porphins in which aryl groups having from sixto 24 carbon atoms are substituted on the bridging carbon atoms of theprophin ring structure which contains four pyrrole nuclei linkedtogether in a circular pattern by four bridging carbon atoms to form agreat ring. Examples of aryl groups which may be substituted in themeso-position of these compounds are phenyl, chlorophenyl,dichlorophenyl, methylphenyl, N,N-dimethylaminophenyl, hydroxyphenyl,naphthyl, biphenyl, anthracyl, phenanthryl, etc. In addition to thesubstituents in the aryl group substituents noted above, the aryl groupscan also have any or a combination of such substituents, e.g., asalkyloxy (one to 20 carbon atoms) substituents such as methoxy, ethoxy,isopropoxy, butoxy, hexyloxy, etc., as well as any other substituentswhich do not change the fundamental aromatic character of the groups.These porphin sensitizers including the above exemplified arylporphins,can have various other substituents, particularly at the beta and beta'positions of the pyrrole rings, e.g., such substituents as lower alkyl(one to 20 carbon atoms) such as vinyl or allyl or alkanoic acid groupssuch as methylcarboxy or ethylcarboxy.

Examples of porphin compounds which are expected to be useful asphotochemical sensitizers in practicing this invention are thearylporphins such as the tetraphenyltetrazoporphins and the complexesthereof, such as diamagnetic complexes, e.g., magnesiumtetraphenyltetrazoporphin, tetraphenyl tetrazoporphin acetate,tetraphenyltetrazoporphin sulfate, zinc tetraphenyltetrazoporphin, andthe meso-aryl porphins including alpha, beta, gamma,delta-naphthylporphin and the diamagnetic metal chelates thereof, e.g.,

tetraphenylporphin

tetrakis(2,4-dichlorophenyl)porphin

tetrakis(2-furyl)porphin

tetrakis(4-methoxyphenyl)porphin

tetrakis(4-methylphenyl)porphin

tetrakis(2-thienyl)porphin

tetraphenylporphin zinc complex

tetrakis(4-nitrophenyl)porphin

tetrakis(4-dimethylaminophenyl)porphin zinc complex;

the tetrabenzomonoazo- and tetrabenzodiazo porphins, the1,2,3,4,5,6,7,8-octaphenylporphins and azoporphins such asoctaphenylporphyrazine, the tetrabenzoporphins, e.g., tetrabenzoporphinand the zinc complex of tetrabenzoporphin.

(2) Other porphin types of photosensitizing materials includechlorophyll, such as chlorophyll α and chlorophyll β, hemin, thetetrazoporphins, chlorophyllin salt derivatives such as the reactionproduct of an alkaline metal chlorophyllin salt and sodium bisulfite,hematoporphin, mercury proto- and hemato-porphins, vitamin B₁₂ and itsderivatives and tetrakis(1-naphthyl)porphin.

(3) Related porphin type materials include the phthalocyanine and metalcomplexes of phthalocyanine such as the zinc and magnesium complexes ofphthalocycanine, as well as phthalocyanine derivatives such as thebarium or calcium salts of the phthalocyanine sulfonic acid, acetylatedphthalocyanine, alkoxy- and aryloxy-benzosubstituted phthalocyanines,5,5',5",5'"-tetraamino-metalphthalocyanine-4,4',4",4'"-tetrasulfonicacid, magnesium tetra(4)methylthiophthalocyanine, arylthioethers ofphthalocyanines, vinyl group containing tetraazoporphins and polymersthereof, mercaptoamino phthalocyanine derivatives and phthalocyanine.

(4) Other photosensitizers include fluorescein type dyes and lightabsorber materials based on a triarylmethane nucleus. Such compounds arewell known and include Crystal Violet, Malachite green, Eosin, RoseBengal and the like.

Polymer preparation routes 1 and 2, above, may actually occurconcurrently during emulsion polymerization or copolymerization ofbutadiene or isoprene.

Suitable polymer substrates can contain varying amounts of sulfidefunctionality. Thus, the photoimaging systems of this invention can besensitive at relatively low levels of sulfur, e.g., as low as 1 mole ofsulfur per 2,500 moles of monomer units. For a typical thiol thisamounts to about 25 mg per 40 g polymer. Even lower levels may bepossible. Higher sulfur levels, e.g., 1 mole of sulfur per mole ofmonomer units have proved operable, and even higher levels are thoughtpossible. Roughly speaking higher levels of sulfur result in higherspeeds, but image quality also is influenced by sulfur content and so aseries of complex variables needs to be balanced for each system.

Film materials can be produced using the photooxidation sensitizedpolymer substrates of this invention by any suitable method. Dependingon the nature of the polymer film formation by coating from an emulsiondispersion, solution or melt of the polymer may be preferable.Illustratively, films may be formed by coating a layer of thepolymer/photosensitizer admixture onto a suitable supporting substrate,such as, polyethylene, polypropylene or MYLAR (polyester) film.

Exposure may be accomplished by any suitable means, such as by the useof a Ascorlux 4 kilowatt pulsed xenon lamp at a distance of 30 inchesfor times ranging from about 1 sec. to 100 sec. The nature of the lightsource, distance of source from film, photopolymer speed, sensitizerlevel and other factors all will influence the time of exposurenecessary to set an image. Exposure may be made through anylight-differentiating target. Typically a silver-type mask is used.

Image development may be effected by a wide variety of techniques. Forexample, development may be accomplished by using solvent to selectivelyremove from the film surface either exposed or non-exposed regions basedupon a differential in solubility resulting from exposure underphotooxidation conditions. Organic developing solvents such as,trichlormethane, trichlorethane, methyl chloroform,methylchloroform-ethanol, benzene and toluene have been successfullyemployed. Aqueous, alcoholic, acid and alkaline developing baths areexpected also to be useful.

Changes in dye receptivity, adhesiveness or tack and other propertychanges between exposed and unexposed regions may also be relied upon asa basis for the development of the latent image.

The developed images may, if desired, be transferred to receivingsupports such as paperboard, cloth, leather, metal, plastic, etc.

It has also been observed that the speed and sensitivity of the systemis markedly improved by the presence of unsaturation in the polymerchain or pendant to it. The reasons may be that the unsaturatedfunctionality serves as a superior pigment binder and/or as a"comonomer" to promote image setting cross-linking in addition to thedimerization of radicals possibly arising from the photooxidized sulfidefunctionality.

The present invention should prove useful for color-proofing, contactfilm, photo printmaking and other graphic arts applications.

Compared with prior art systems relying upon photooxidation of polymerunsaturation to produce a latent hydroperoxidized polymer image, thepresent systems allow photoimaging to be accomplished in one to twoorders of magnitude shorter time (or equivalent less radiation, lesssensitizer, etc.) than is required for hydroperoxide imaging. Inaddition the present system requires less oxygen for image setting whichis of importance where the exposure step is operated under oxygenrestricted conditions, as for example, when exposure is carried out in avacuum frame.

The invention will be appreciated more fully by reference to thefollowing examples which are intended to be illustrative and notlimiting.

EXAMPLE 1

A polymer was prepared by emulsion polymerization employing thefollowing components: 40 g styrene, 2.0 g of 55% divinylbenzene, 0.2 gn-dodecylmercaptan, 83 g oxygen-free water, 1.2 g sodium lauryl sulfate,0.1 g ammonium persulfate and 0.1 g sodium sulfite. From the dryisolated powdery product was prepared a dispersion by mixing 8 g polymerwith 92 g benzene. To this dispersion was added 40 mg (5 mg/g polymer)of tetraphenylporphin (TPP). A cover of Al foil was provided for thebottle. When the sensitizer had dissolved about 1 gm of cyan pigmentgrind was added per fifteen grams of sensitized polymer dispersion andthen shaken. A film of sensitized pigmented dispersion was drawn on asheet of 0.5 ml polypropylene laminated to a 3 mil MYLAR sheet using awire-wound rod of size 8 to 16 in subdued light. On air drying in thedark a photoactive film of about 1 micron thickness was formed.

The desired image to be copied, a transparency or silver negative, wasplaced on the photosensitized sheet as prepared above. To insure goodcontact between photo-active sheet and the target the two may be placedin a glass vacuum frame (NuArc Company). The composite was then exposedto the radiation of an Ascorlux (American Speedlight Corp.) pulsed xenon4 kilowatt lamp at a distance of 30 in. for about twenty seconds. (Thisis principally visible radiation in the 360-800 micron range.) Afterexposure the pigmented photoactive film visually looked the same asbefore exposure. When placed in a pan and covered with methylchloroform, the regions of the photoactive layer not exposed toradiation redisperse while those exposed to radiation remain in place (anegative-working process). This developing process generally requiresfrom 15 to 20 seconds. The polypropylene/MYLAR substrate sheet on whichis the developed cyan image is then removed from the bath and air driedbriefly.

EXAMPLE 2

A polymer was prepared by emulsion polymerization employing 40 gstyrene, 2.0 g trimethylolpropane trimethacrylate, 0.2 g n-butylthioglycolate, 83 g oxygen-free water, 1.2 g sodium lauryl sulfate, 0.1g ammonium persulfate and 0.1 g sodium sulfite. It was tested as inExample 1 except that a magenta pigment was employed. A good image wasobtainable on 15 sec. exposure.

EXAMPLE 3

Example 1 was repeated except that no n-dodecylmercaptan was used. Noimage was obtained after 50 seconds exposure.

EXAMPLE 4

Styrene, 34 g, 6 g butadiene, 0.5 g. bromoform 83 g oxygen-free water,1.2 g sodium lauryl sulfate, 0.1 g ammonium persulfate and 0.1 g sodiumsulfite were emulsion copolymerized. The product was tested as inExample 1 and found not to form an image in 50 seconds exposure.

A latex of material using the above formulation was prepared unexposedto air. To it was added 1 g of n-butyl thioglycolate, 0.1 ammoniumpersulfate and 0.1 sodium sulfite. The mixture was agitated at 50° C.for 18 hours under nitrogen after which the polymer was isolated. Asatisfactory yellow pigmented image was developed in benzene using thismaterial exposed for 15 seconds with the radiation source of Example 1but also using a neutral density filter which allowed only 0.09 of theincident radiation to reach the film. "1/2A" 5% coverage dots were heldand 95% coverage "M" dots were open when a half tone silver image maskwas used.

EXAMPLE 5

An emulsion polymerization was carried out at 50° C. for 18 hours using32 g styrene, 1.6 g of 55% divinylbenzene, 0.5 g bromoform, 8 gbutadiene, 83 g oxygen-free water, 1.2 g sodium lauryl sulfate, 0.1 gammonium persulfate and 0.1 g sodium sulfite. The product polymer wasisolated by precipitation in methanol and dried. 7.2 g was dispersed in84 g benzene. Then 0.6 g n-butyl thioglycolate and 0.1 g recrystallizedazobisisobutyronitrile were added and the mixture held at 50° C. for 18hours. The product polymer was isolated and a cyan-pigmented film drawnin a photographic darkroom using a red safelight as in Example 1. Thefilm was exposed 3 sec. using the source of Example 1 and a neutraldensity filter to decrease incident radiation by a factor of 0.09. Ondevelopment in benzene a satisfactory image was obtained.

EXAMPLE 6

An emulsion polymerization was conducted using 34 g methyl methacrylate,1.5 g trimethyloltrimethacrylate, 6.0 g butadiene, 83 g oxygen-freedistilled water, 1.2 g sodium lauryl sulfate, 0.1 g ammonium persulfateand 0.1 g sodium sulfate. The polymer product was isolated and drawn asa cyan pigmented film as per Example 1. No image was obtained upon 50sec. exposure and subsequent development.

The same composition as above was prepared except that 0.2 g oft-dodecyl mercaptan was also added before the polymerization wasinitiated. Using this product as in Example 1, image were attainableusing 10 sec. of exposure from the source in Example 1 attenuated by afilter to 60% of its full value.

EXAMPLE 7

A cyan-pigmented film of poly(ethylthioethyl methacrylate) was preparedand exposed as in Example 1. After 20 sec. exposure and development ineither methyl chloroform +5% ethanol or in toluene, a visible image wasobtained although the image quality in terms of fidelity and resolutionwas not as good as the images obtained with the systems exemplifiedabove.

EXAMPLE 8

An emulsion polymerization was conducted using 34 g styrene, 1 gethylthioethyl methacrylate, 6.0 g butadiene, 0.1 n-dodecyl mercaptan,83 g oxygen-free water, 1.2 g sodium lauryl sulfate, 0.1 g ammoniumpersulfate and 0.1 g sodium sulfite. The resulting polymer was isolatedand drawn as a pigmented film as by the procedure of Example 1. An imagewas obtained on 5 sec. exposure with the source radiation beingattenuated by a factor of 0.09 through a neutral density filter whendeveloped in methyl chloroform +5% ethanol.

EXAMPLE 9

An emulsion polymerization was conducted as in Example 8 except using 84g methyl methacrylate in place of the styrene. An image was obtainedwhen developed after 45 sec. under the radiation source of Example 1without any attenuation.

EXAMPLE 10

An emulsion polymerization was carried out using 29 g methylmethacrylate, 5 g ethylthioethyl methacrylate, 2.0 g trimethylolpropanetrimethacrylate, 4.2 g butadiene, 0.2 g n-dodecyl mercaptan, 83 goxygen-free water, 0.1 g ammonium persulfate and 0.1 g sodium sulfite.The isolated polymer product was drawn as a sensitized, pigmented filmas in Example 1. A satisfactory image was obtained after developmentexposure to 15 sec. of radiation from the source of Example 1 attenuatedby a factor of 0.09.

EXAMPLE 11

An emulsion polymerization was conducted using 25 gethylthioethylmethacrylate, 5.0 g butadiene, 1.2 g trimethylpropanetrimethacrylate, 0.1 g n-dodecylmercaptan, 83 g oxygen-free water, 1.2 gsodium lauryl sulfite, 0.1 g ammonium persulfate and 0.1 g sodiumsulfite. The isolated polymer was drawn as a sensitized pigmented filmas in Example 1. A high quality image was obtained on two secondsexposure to a flux of 4×10⁴ ergs/cm² /sec sensitized at a level of 0.1wt% tetraphenylporphin. In this example a light meter was used tomeasure intensity of exposure.

EXAMPLE 12

An emulsion polymer was prepared using 29 g styrene, 1.6 gtrimethylpropane triacrylate, 7.6 g of ##STR6## 0.7 g n-dodecylmercaptan, 6.0 g outadiene and the water emulsifier and initiators ofExample 11. A good image was obtained on two second exposure to avisible flux of 4.0×10⁴ ergs/cm² /sec at a tetraphenylporphin level of0.1 wt%.

EXAMPLE 13

An emulsion polymer was formed using 29 g methylmethacrylate, 5.9 g##STR7## 6.0 g butadiene, 1.6 g trimethylpropane triacrylate and 0.2 gn-dodecyl mercaptan as in Example 11. Imaging behavior similar to thatobtained in Example 10 was observed.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

What is claimed is:
 1. A photoimageable polymeric element comprising a body of polymeric material containing organic sulfide functionality and a photooxidation sensitizer, said sensitizer and said sulfide functionally being present in an amount sufficient so that upon exposure to irradiation in the presence of oxygen a developable latent image is produced in said polymeric material, said exposure being of an intensity insufficient to produce a latent image in the absence of said sulfide functionality.
 2. The element of claim 1 wherein said body of polymeric material further contains ##STR8## unsaturation.
 3. The element of claim 1 wherein said body of polymeric material is produced by polymerizing monomeric material in the presence of a thiol or disulfide and a cross-linking agent.
 4. The element of claim 3 wherein said body of polymeric material contains discrete, cross-linked particle form polymer produced by emulsion polymerization.
 5. The element of claim 4 wherein said body of polymeric material further contains ##STR9## unsaturation.
 6. The element of claim 1 wherein said body of polymeric material comprises a preformed polymer having said sulfide functionality introduced into said polymer at reactive sites.
 7. The element of claim 6 wherein said reactive sites comprise unsaturated ##STR10## sites.
 8. The element of claim 6 wherein said preformed polymer is cross-linked.
 9. The element of claim 1 wherein said body of polymeric material is the polymerization or copolymerization product of at least one sulfide containing monomer.
 10. The element of claim 9 wherein said sulfide containing monomer is selected from the group consisting of vinyl sulfides and ethylthioethyl methacrylates.
 11. The element of claim 1 wherein said body of polymeric material comprises a polymer with --S-- or --S--S-- units in the main polymer chain.
 12. The element of claim 11 wherein said body of polymeric material comprises polyethylene sulfide.
 13. The element of claim 11 wherein said body of polymeric material comprises polypropylene sulfide.
 14. The element of claim 11 wherein said body of polymeric material comprises polysulfides.
 15. The element of claim 1 wherein said body of polymeric material contains a polyolefin.
 16. The element of claim 15 wherein said body of polymeric material contains polyethylene.
 17. The element of claim 15 wherein said body of polymeric material contains polypropylene.
 18. The element of claim 1 wherein said body of polymeric material contains a polydiolefin.
 19. The element of claim 18 wherein said body of polymeric material contains a polybutadiene.
 20. The element of claim 1 wherein said body of polymeric material contains a polymer of an alpha, betaunsaturated carboxylic acid ester.
 21. The element of claim 20 wherein said body of polymeric material contains a polyacrylate polymer.
 22. The element of claim 20 wherein said body of polymeric material contains a polymethacrylate polymer.
 23. The element of claim 1 wherein said body of polymeric material contains a polyvinyl aromatic polymer.
 24. The element of claim 23 wherein said body of polymeric material contains a polystyrene.
 25. The element of claim 1 wherein said body of polymeric material contains a polyvinylidene polymer.
 26. The element of claim 1 wherein said body of polymeric material contains a condensation polymer.
 27. The element of claim 26 wherein said body of polymeric material contains a phenol-formaldehyde polymer.
 28. The element of claim 1 wherein said body of polymeric material contains a polyamide polymer.
 29. The element of claim 28 wherein said polyamide polymer is nylon.
 30. The element of claim 1 which upon selective exposure to irradiation in the presence of oxygen and a photooxidation sensitizer is characterized by a relative difference in one or more physical or chemical properties in the exposed and unexposed regions such that said latent image may be developed.
 31. The element of claim 30 wherein said difference is in relative solubility in a developing solvent.
 32. The element of claim 30 wherein said difference is in relative dye receptivity to a developing dye.
 33. The element of claim 30 wherein said difference is in relative adhesiveness or tack to a given substrate.
 34. The element of claim 1 wherein a photooxidation sensitizer is incorporated into said body of polymeric material.
 35. The element of claim 34 wherein said photooxidation sensitizer is a porphin.
 36. The element of claim 35 wherein said porphin is tetraphenylporphin.
 37. The element of claim 34 wherein said photooxidation sensitizer is dinaphthylene thiophene.
 38. The element of claim 34 wherein said photooxidation sensitizer is rose bengal.
 39. The element of claim 1 wherein said body of polymeric material is in the form of a thin film.
 40. The element of claim 39 further comprising a support for said thin film.
 41. The element of claim 40 wherein said support is a second thin film or layer to which said thin film of said body of polymeric material is temporarily or permanently bonded. 